DebugInfo: Scope for condition variables more narrowly than the loop variable.

for loops introduce two scopes - one for the outer loop variable and its
initialization, and another for the body of the loop, including any
variable declared inside the loop condition.

llvm-svn: 216288

3 files changed, 40 insertions, 32 deletions

diff --git a/clang/lib/CodeGen/CGStmt.cpp b/clang/lib/CodeGen/CGStmt.cpp
index 1395d60ab07..de3b795fc2b 100644
--- a/clang/lib/CodeGen/CGStmt.cpp
+++ b/clang/lib/CodeGen/CGStmt.cpp
@@ -810,11 +810,7 @@ void CodeGenFunction::EmitForStmt(const ForStmt &S,
                                   const ArrayRef<const Attr *> &ForAttrs) {
   JumpDest LoopExit = getJumpDestInCurrentScope("for.end");
 
-  RunCleanupsScope ForScope(*this);
-
-  CGDebugInfo *DI = getDebugInfo();
-  if (DI)
-    DI->EmitLexicalBlockStart(Builder, S.getSourceRange().getBegin());
+  LexicalScope ForScope(*this, S.getSourceRange());
 
   // Evaluate the first part before the loop.
   if (S.getInit())
@@ -842,7 +838,7 @@ void CodeGenFunction::EmitForStmt(const ForStmt &S,
   BreakContinueStack.push_back(BreakContinue(LoopExit, Continue));
 
   // Create a cleanup scope for the condition variable cleanups.
-  RunCleanupsScope ConditionScope(*this);
+  LexicalScope ConditionScope(*this, S.getSourceRange());
 
   if (S.getCond()) {
     // If the for statement has a condition scope, emit the local variable
@@ -902,9 +898,6 @@ void CodeGenFunction::EmitForStmt(const ForStmt &S,
 
   ForScope.ForceCleanup();
 
-  if (DI)
-    DI->EmitLexicalBlockEnd(Builder, S.getSourceRange().getEnd());
-
   LoopStack.pop();
 
   // Emit the fall-through block.
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 04294ec8e57..6d21e78bf23 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -535,7 +535,7 @@ public:
     }
   };
 
-  class LexicalScope: protected RunCleanupsScope {
+  class LexicalScope : public RunCleanupsScope {
     SourceRange Range;
     SmallVector<const LabelDecl*, 4> Labels;
     LexicalScope *ParentScope;
diff --git a/clang/test/CodeGenCXX/debug-info-scope.cpp b/clang/test/CodeGenCXX/debug-info-scope.cpp
index 0447dc04d56..58195e37782 100644
--- a/clang/test/CodeGenCXX/debug-info-scope.cpp
+++ b/clang/test/CodeGenCXX/debug-info-scope.cpp
@@ -3,30 +3,45 @@
 // Two variables with the same name in subsequent if staments need to be in separate scopes.
 //
 // rdar://problem/14024005
-//
 
-int printf(const char*, ...);
+int src();
 
-char *return_char (int input)
-{
-  if (input%2 == 0)
-    return "I am even.\n";
-  else
-    return "I am odd.\n";
-}
+void f();
 
-int main2() {
-// CHECK: [ DW_TAG_auto_variable ] [ptr] [line [[@LINE+2]]]
-// CHECK: metadata !{i32 {{.*}}, metadata !{{.*}}, i32 [[@LINE+1]], {{.*}}} ; [ DW_TAG_lexical_block ]
-  if (char *ptr = return_char(1)) {
-    printf ("%s", ptr);
-  }
-// CHECK: [ DW_TAG_auto_variable ] [ptr] [line [[@LINE+2]]]
-// CHECK: metadata !{i32 {{.*}}, metadata !{{.*}}, i32 [[@LINE+1]], {{.*}}} ; [ DW_TAG_lexical_block ]
-  if (char *ptr = return_char(2)) {
-    printf ("%s", ptr);
-  }
-  else printf ("%s", ptr);
+void func() {
+  // CHECK: = metadata !{i32 786688, metadata [[IF1:![0-9]*]], {{.*}} ; [ DW_TAG_auto_variable ] [i] [line [[@LINE+2]]]
+  // CHECK: [[IF1]] = metadata !{i32 {{.*}}, metadata !{{.*}}, i32 [[@LINE+1]], {{.*}}} ; [ DW_TAG_lexical_block ]
+  if (int i = src())
+    f();
 
-  return 0;
+  // CHECK: = metadata !{i32 786688, metadata [[IF2:![0-9]*]], {{.*}} ; [ DW_TAG_auto_variable ] [i] [line [[@LINE+2]]]
+  // CHECK: [[IF2]] = metadata !{i32 {{.*}}, metadata !{{.*}}, i32 [[@LINE+1]], {{.*}}} ; [ DW_TAG_lexical_block ]
+  if (int i = src()) {
+    f();
+  } else
+    f();
+
+  // CHECK: = metadata !{i32 786688, metadata [[FOR:![0-9]*]], {{.*}} ; [ DW_TAG_auto_variable ] [i] [line [[@LINE+2]]]
+  // CHECK: [[FOR]] = metadata !{i32 {{.*}}, metadata !{{.*}}, i32 [[@LINE+1]], {{.*}}} ; [ DW_TAG_lexical_block ]
+  for (int i = 0;
+  // CHECK: = metadata !{i32 786688, metadata [[FOR_BODY:![0-9]*]], {{.*}} ; [ DW_TAG_auto_variable ] [b] [line [[@LINE+6]]]
+  // The scope could be located at 'bool b', but LLVM drops line information for
+  // scopes anyway, so it's not terribly important.
+  // FIXME: change the debug info schema to not include locations of scopes,
+  // since they're not used.
+  // CHECK: [[FOR_BODY]] = metadata !{i32 {{.*}}, metadata [[FOR]], i32 [[@LINE-6]], {{.*}}} ; [ DW_TAG_lexical_block ]
+       bool b = i != 10; ++i)
+    f();
+
+  // CHECK: = metadata !{i32 786688, metadata [[FOR:![0-9]*]], {{.*}} ; [ DW_TAG_auto_variable ] [i] [line [[@LINE+2]]]
+  // CHECK: [[FOR]] = metadata !{i32 {{.*}}, metadata !{{.*}}, i32 [[@LINE+1]], {{.*}}} ; [ DW_TAG_lexical_block ]
+  for (int i = 0; i != 10; ++i) {
+  // FIXME: Do not include scopes that have only other scopes (and no variables
+  // or using declarations) as direct children, they just waste
+  // space/relocations/etc.
+  // CHECK: [[FOR_BODY:![0-9]*]] = metadata !{i32 {{.*}}, metadata [[FOR]], i32 [[@LINE-4]], {{.*}}} ; [ DW_TAG_lexical_block ]
+  // CHECK: = metadata !{i32 786688, metadata [[FOR_COMPOUND:![0-9]*]], {{.*}} ; [ DW_TAG_auto_variable ] [b] [line [[@LINE+2]]]
+  // CHECK: [[FOR_COMPOUND]] = metadata !{i32 {{.*}}, metadata [[FOR_BODY]], i32 [[@LINE-6]], {{.*}}} ; [ DW_TAG_lexical_block ]
+    bool b = i % 2;
+  }
 }